The scarred foundation of the World Trade Center shielded behind glass, a memorial pit 30 feet below street level, and a spindly spire with a 110th-floor restaurant – those are among the new twists in a rejiggered plan unveiled yesterday by winning Ground Zero architect Daniel Libeskind.

But even with the changes to his original design, many questions remain about the future of the scheme – including which agency will hire Libeskind, who was praised yesterday by Mayor Bloomberg and Gov. Pataki at a press conference officially announcing his selection.

* The 1,776-foot-tall spire – the world’s tallest – would contain a restaurant on the 110th floor, replacing the destroyed Windows of the World.

One of the elements that is likely to raise eyebrows is the design’s preoccupation with the decaying concrete wall of the WTC basement. This wall, never a visible part of the Twin Towers, was hidden for months after the 9/11 attacks until excavators cleared the debris.

But Libeskind wants to put the wall on display as symbol of the durability of American democracy.

In fact, Libeskind wants to encase it behind viewing glass in a climate-controlled space.

Who pays Libeskind could ultimately determine what gets done downtown – depending on whether it’s the Port Authority, which owns the trade-center site, or the Lower Manhattan Development Corp., which has a more advisory role.

“This all has to be ironed out,” said PA Executive Director Joe Seymour.

“Daniel will have to have input on the memorial competition, and we want to have Daniel’s input on designing [the Ground Zero rail terminal] . . . This is a vision. Obviously, everyone hopes the majority of it will be upheld.”

Trade-center leaseholder Larry Silverstein criticized an earlier version of the plan, but he praised it yesterday.

“He says the Libeskind plan is exactly what was required and is a perfect site plan,” said Silverstein’s spokesman, Howard Rubenstein.

Libeskind pleased Silverstein by increasing the office space on the site to cover all 10 million square feet lost on 9/11.